Abstract: A lapping plate topography system includes a measuring apparatus for measuring the surface of a lapping plate, and an analysis apparatus for analyzing and presenting the data resulting from such measurements. The measurement apparatus has a non-contacting capacitive probe for measuring a height of the surface of the lapping plate, a rotary arm assembly for moving the probe in an arc over the surface of the lapping plate, and a spindle assembly for rotating the lapping plate about its center. The computer-based analysis apparatus is operable to input from the measurement apparatus the measured height at a plurality of data points on the surface of the lapping plate, calculate Fourier transform harmonic coefficients based on the plurality of measured heights, calculate surface ripple coefficients based on the calculated Fourier transform harmonic coefficients, and output the calculated surface ripple coefficients to an appropriate display device.

Abstract: A lapping plate topography system includes a measuring apparatus for measuring the surface of a lapping plate, and an analysis apparatus for analyzing and presenting the data resulting from such measurements. The measurement apparatus has a non-contacting capacitive probe for measuring a height of the surface of the lapping plate, a rotary arm assembly for moving the probe in an arc over the surface of the lapping plate, and a spindle assembly for rotating the lapping plate about its center. The computer-based analysis apparatus is operable to input from the measurement apparatus the measured height at a plurality of data points on the surface of the lapping plate, calculate Fourier transform harmonic coefficients based on the plurality of measured heights, calculate surface ripple coefficients based on the calculated Fourier transform harmonic coefficients, and output the calculated surface ripple coefficients to an appropriate display device.

Abstract: An apparatus and method of reclaiming a disk substrate. The cost of reclaiming a disk substrate can be lower, and the quality higher, than making a new one from a blank. A layer of a data storage disk is stripped, e.g., by acid/oxidizing bath immersion. The stripped disk is polished in a carrier between polishing pads, with the relative velocity of the polishing pads as seen by the disk being precisely controlled so that an equal amount of stock is removed from each side. Preferably, several stripped disks are sorted into groups based on disk thickness, and disks from one of the groups are simultaneously polished in the carrier. Sorting improves stock removal uniformity from disk to disk. The polished disks are cleaned and, preferably, ordered in a cassette for stacking in a storage device based on disk thickness to more easily meet a mean center specification.

Abstract: A glass disk is illuminated through an edge and an image of a segment of the disk edge is captured by a CCD camera. If internally reflected light is refracted and diffused by an anomaly in a disk edge, the anomaly will appear as a brilliant light spot on the image. Brilliant spots on a disk edge are detected as bright pixels; and within inspection zones, rows of pixels or areas of pixels are compared with a threshold value. Pixel strings having illumination intensity greater than the threshold are counted; and whenever the resulting count is larger than a predetermined number, the disk is rejected as having an anomaly of a size warranting rejection. In inspection area zones, pixel counts of intensities greater than a threshold value warrant rejection.

Abstract: A device and associated method useful for determining whether a disk has a chipped edge. The preferred device includes a laser that radiates a laser beam to the disk in the vicinity of its edge. The preferred device also includes a radiation detector for detecting electromagnetic radiation from the laser after the radiation has been transmitted, reflected, retracted or scattered by the disk. A chip in the vicinity of the edge of the disk will direct the electromagnetic radiation differently than an intact disk edge. Therefore, the radiation detector can utilize changes in the detected electromagnetic radiation in order to determine whether the edge of the disk is intact or whether it has a defect, such as an edge chip.